Field of the Invention
The present disclosure relates to a display device.
Discussion of the Related Art
Various flat display devices capable of reducing weight and volume, that is, disadvantages of a cathode ray tube (CRT), have recently been developed. Examples of such flat display devices include a liquid crystal display (LCD) device, a field emission display (FED), a plasma display panel (PDP) and an organic light-emitting display (OLED). Among them, the organic light-emitting display is a self-emission display that emits light by exciting an organic compound, and enables lightness and thinness because it does not require backlight unit used in an LCD and can simplify the process. Furthermore, the OLED can be fabricated at a low temperature, has a fast response time of 1 ms or less, and has characteristics, such as low consumption power, a wide viewing angle, and high contrast.
The organic light-emitting display generally includes a light-emitting layer made of an organic substance between a first electrode, that is, the anode, and a second electrode, that is, the cathode. Holes supplied from the first electrode and electrons supplied from the second electrode are combined in the light-emitting layer to form exciton, that is, hole-electron pairs. Light is emitted by energy generated when the exciton returns to the ground state.
The organic light-emitting display is partitioned into a display region including a plurality of pixels and displaying an image and a non-display region, that is, a region other than the display region. A data pad part for applying a data driving signal to the plurality of pixels is disposed in the non-display region. The data pad part includes a plurality of wires extending from the display region. A plurality of pad electrodes is connected to the plurality of wires through contact holes. In order to prevent a pad electrode from being lost due to subsequent process in a contact hole region, an insulating film covering the contact hole region is disposed.
However, the insulating film that covers the contact hole region has a problem in that it is peeled off because an adhesive force is weakened depending on a layer coming into contact with the bottom of the insulating film. Accordingly, there are problems in that a defect occurs in the connection with a data driving part because a pad electrode disposed in the contact hole region is lost and reliability of the organic light-emitting display is deteriorated.